About "Enabled(Object contributes to the fluid simulation)"
In my experience, the Enabled checkbox doesn't seem to give the desired behaviour - in fact, I've just tested this on Blender 2.79.6 and the Enabled checkbox doesn't seem to enable or disable the Control object at all (all it does do is "grey-out" the controls to allow the Control force to be adjusted.

However, instead of keyframing the Enabled checkbox you can enable and disable the effect by simply keyframing the Strength - with zero being effectively 'disabled' and non-zero (higher values for more force) to effectively 'Enable' the control object.

I believe in your example the control object is effectively always enabled.